Agricultural implements, such as planters and seed dispensers, typically include a system of conduits through which a dispensed product, such as seed, is distributed. In addition, a fluid, such as pressurized air, also moves through the system of conduits to move the dispensed product to different locations on the agricultural implement. For example, some current agricultural implements include conduits through which the product is transferred from a primary container to one or more metering devices, such as singulators. However, most current designs use a large volume of fluid at low pressure to move a low volume of the dispensed product; as a result, current designs are relatively inefficient.
Moving the dispensed product with a low pressure fluid has other drawbacks in addition to low system efficiency. For example, in order to provide an adequate volume of the product to the metering devices, a relatively high air flow rate is used in which a relatively low volume of the product is transported in a high volume of the fluid, which is referred to as dilute phase flow. A high air flow rate results in high product velocity, which can in turn damage the dispensed product and the conduits of the agricultural implement. As another example, the dispensed product may become lodged in the conduits if the air velocity falls below the critical level. Most current systems do not have sufficient power to dislodge the product within the conduits. As a result, the lodged product may require manual removal by an operator which may in turn result in down-time of the agricultural implement and in some cases loss of product.
To address the drawbacks of the aforementioned systems, the inventors of the present invention designed the agricultural implement with dense phase product flow described in U.S. patent application Ser. No. 12/271,679, which is hereby incorporated by reference as if fully set forth herein. The agricultural implement with dense phase product flow advantageously provides a system in which flow of the product may be stopped without the product becoming lodged in the system conduits upon restarting flow of the product. However, some of the dispensed product remains in the system of conduits after completing a dispensing operation, and it may be wasteful to discharge the residual product by continuing the normal operation of the system. In addition, the system of conduits does not provide an adequate storage location for the dispensed product, and the dispensed product may deteriorate before a subsequent use of the agricultural implement.
Therefore, it would be desirable to have a dense phase product flow delivery system that is capable of purging the residual product in system conduits after an operation has been completed. In addition, it would also be desirable to purge the residual product in a manner such that the residual product is not wasted. Further still, it would also be desirable to purge the residual product in an efficient manner and move the product a relatively low velocity to reduce wear to the system.